Method and apparatus for printing on workpieces with an outer surface having the form of a truncated cone

ABSTRACT

Method and apparatus for printing on the surface of a noncylindrical workpiece moving against a printing block with a printing tape therebetween in which both an angular and a straight line motion is imparted to the tape.

United States Patent [191 Blattner [451 Feb. 25, 1975 METHOD ANDAPPARATUS FOR PRINTING ON WORKPIECES WITH AN OUTER SURFACE HAVING THEFORM OF A TRUNCATED CONE [75] Inventor: Kurt Blattner, Dietikon,Switzerland [73] Assignee: MADAG Maschinenund Apparatebau Dietikon AG,Dietikon, Switzerland [22] Filed: June 8, 1973 [21] Appl. No.: 368,255

[30] Foreign Application Priority Data June 14, 1972 Switzerland 8861/72[52] U.S. Cl ..101/7,101/32, 101/38 R, 101/426, 156/234, 156/540,197/151 [51] Int. Cl B411 17/28 [58] Field of Search 101/7, 5, 38 A, 40,38 R, 101/39, 426; 156/234, 540; 197/151, 158

[56] References Cited UNITED STATES PATENTS 153,962 8/1874 Jennings101/38 R 2,288,298 6/1942 Norman et all 101/38 A X 1 3,309,256 3/1967Warsager 3,613,857 10/1971 Thevis et al. 197/158 X FOREIGN PATENTS ORAPPLICATIONS 613,023 11/1948 Great Britain .1 101/39 1,097,507 1/1968Great Britain 101/38 R Primary Examiner-Clifford D. Crowder Attorney,Agent, or FirmDarby & Darby [57] ABSTRACT Method and apparatus forprinting on the surface of a non-cylindrical workpiece moving against aprinting block with a printing tape therebetween in which both anangular and a straight line motion is imparted to the tape.

10 Claims, 3 Drawing Figures 1 METHOD AND APPARATUS FOR PRINTING ONWORKPIECES WITH AN OUTER SURFACE HAVING THE FORM OF A TRUNCATED CONE Thepresent invention concerns a method and apparatus for printing onworkpieces whose outer surfaces are non-cylindrical, such as in the formof a truncated cone, by using an embossing band arranged between a blockand the workpiece.

When printing on a workpiece whose outer surface has the form of acylinder it has already been suggested, in order to permit aspace-saving construction, to also design the printing block in the formof a cylinder and to press the workpiece, which is held loosely on amandrel, for printing against the revolving block with the interpositionof an embossing band. The rotary movement is transmitted by friction tothe workpiece and the printing is effected without the lateral movementof the workpiece or block.

This general construction idea, namely to give the block and theworkpiece a corresponding form to achieve the above mentionedadvantages, can not be simply transposed in methods and devices forprinting on workpieces whose outer surfaces are noncylindrical, such asin the form of a truncated cone, since the embossing band would becaused to move less rapidly in the range of the smaller diameterposition than in the range of the larger diameter portions of the cone.This would lead to destruction of the embossing band.

In addition, the use of plane blocks which one had to utilize in view ofthe above mentioned difficulties at the expense of a space-blockingconstruction, had the additional disadvantage that the printing picturenaturally had to be applied on this plane block in the shape of thedevelopment of the truncated cone of the workpiece. This made theproduction of the block much more difficult.

The present invention provides a method and an apparatus for printing onworkpieces with a noncylindrical outer surface, such as one having theform of a truncated cone, which permits, on the one hand, a space-savingconstruction without relative movements between block and workpiece, asit is the case with the use of plane blocks, and which permitsapplication of the printing picture in a simple manner on the block.

In the method according to the invention a printing block is used whoseouter form corresponds to the workpiece. The block is rotated about itsgeometric axis and an angular pivoting movement about an imaginary axisextending perpendicularly to the surface of the block is imparted to theembossing band. The pivoting motion depends on the conicity of theworkpiece in such a way that the center of the roll-off ring of theblock on the embossing band coincides with the geometric apex of thetruncated cone form of the block.

The device for carrying out this method in turn includes a pivotmechanism for the first arm of a parallel guide, the embossing bandbeing so arranged on a second arm extending parallel to the first armthat its feeding direction is parallel to the second arm.

An embodiment of the device according to the invention is representedschematicallyin the drawing, which also shows an embodiment of themethod according to the invention as well as a development process. Inthe drawings:

FIG. 1 is a schematic top view of an appratus according to theinvention;

FIG. 2 shows the same view of a block and of the workpiece in thedirection of the arrow A in FIG. 1; and

FIG. 3 is a representation of the development process.

In FIGS. 1 and 2 the printing block 1, having the printing informationthereon, for example in the form of a die or engraving, is secured on ablock carrier 2 and is revolved about its geometric axis. This blockcarrier is driven in the represented embodiment by two bevel gears 3 and4, bevel gear 4 being connected to a pinion 5 which meshes with a rack 8connected with a pushrod 6 of a hydraulic driving unit 7. As can be seenin FIG. 2, the workpiece 9 in the form of a hollow truncated cone isarranged below the block 1 and rotates loosely on a mandrel 10 so thatthe block and workpiece are in contact with each other along adirectrix, with the interposition of an embossing band 11. The workpieceis pressed against the block I with the interposition of the embossingband 11, by means not shown here, so that when block 1 is set inrotation by the above-described driving unit 3-8,. the block andworkpiece hob on one another and the printing picture is transmittedthrough band 11 to the workpiece.

The embossing band 11 is entrained by this hobbing movement betweenblock 1 and workpiece 9 and is unwound from a supply roll 12 and woundon a roll 14 driven by a driving unit 13. Both rolls l2 and 14 are heldeach in a fork, or bracket 15. The forks are, on the one hand, connectedwith each other by a bar 25 offset from the center of the forks. Eachfork is articulated, on the other hand, by a connection to one end of are spective guide rod l6 each of whose other ends are connected to anadditional guide rod 17. The forks l5 and the bars 25 form thus one armof a parallelogram guide on which the rolls 12 and 14 as well as theembossing band 11 are held. The guide rods 16 and 17 form the othersides. A pinion 18 is connected with the guide rod 17 and meshes with arack 20 having an extension 26. The extension 26 has a head 27 which isheld and can move in a longitudinal groove 21 of a guide piece 19. Theguide piece 19' rotates about a journal 22 rigidly connected with thepushrod 6 and is articulated at its end remote of the head 27 at pivot24 by an adjusting device 23. This arrangement permits the angle betweenthe geometric longitudinal axis of the guide piece 19 and the push-rod 6to be adjusted.

If an axial movement in the direction of the arrow B in FIG. 1 isimparted to the pushrod 6 to drive the block, not only block 1 is set inrevolution in the above described manner through elements 8, 5, 4, 3, 2,but at the same time the guide piece 19 is entrained in the samedirection. As guide piece 19 moves the head 27 is displaced in thelongitudinal groove 21 toward the journal 22, that is, to the right inFIG. 1. This displacement is transmitted through a pivoting mechanism,including a guide piece 19, rack 20 and pinion 18, to the guide rod 17and thus to the forks l5 and the embossing band 11. The amount and thedirection of the angular pivoting movement is determined by the positionof the fulcrum 24 of the adjusting device 23 relative to the pushrod 6.If the fulcrum is displaced into a plane passing through the pushrod 6,an angular pivot movement can be prevented completely in which case theapparatus can be used for printing on workpieces with an outer surfacein the form of a cylinder. If the fulcrum 24 is displaced to the left ofpush rod 6, with regard to the drawing, the embossing band 11 is pivotedin the opposite direction.

As far as the method of operation is concerned, the center of thehobbing surface 33 of the truncated block 1 must lie on the embossingband 11 along a line 29 projected from the (imaginary) apex X of thetruncated cone. It is possible, and for certain applications evenexpedient, to form the parallelogram 15, 16, 17, 25 by a suitableselection of the lengths of the guide rods 16. However, such anarrangement has a disadvantage in that the lengths of the guide rods 16must always be changed when embossing workpieces of different conicity.In order to avoid this disadvantage, the arrangement is such that theembossing band 11 and the rolls l2 and 14 respectively, as well as theforks 15 are turned about the intersection Y of the center line 28 ofthe embossing band with the contact line 29 between block 1 and theembossing band 11. In this arrangement the length of the guide rods neednot be changed, regardless of the conicity of the workpiece or of theblock.

In order to achieve that the development lies on annular ring segment 33(also shown by lines 30 and 31 in FIG. 1) with the center in X, despitethe fact that the angular pivoting movement takes place not about X butabout Y, an axial advance movement is imparted to the embossing bandadditionally by the motor 13. The movement of the embossing band 11 isthus a combined movement and it is composed, on the one hand, of apivoting movement about the center Y, and on the other hand, of an axialadvance movement.

The combined movement is represented in the diagram in FIG. 3, dividedinto the two partial movements. Starting from an assumed neutralposition, in which the contact line between the block and the embossingband corresponds to the line C Y D, the advance movement takes placefirst in the direction of the center line 28 of the embossing band bywhich the points C, Y and D are transported to Cl, Y1 and D1. The pointsC1 and D1 are outside the boundary lines 31 and 30 of the roll offsurface 33. If a pivot movement about the center Y1 follows, the saidpoints C and D move to C2 and D2, the pivot angle being given by theconicity of the workpiece and of the block and corresponding to thattransmitted within the respective time interval over the guide piece 19,head 27, extension 26, rack and pinion 18 to the parallelogram l6, 17,25.

By the following advance movement, which is perpendicular to the lineC2, D2, the points move to C3, Y3, D3 which lie again on the boundarylines and 31 and on the center line 32 respectively, of the roll-offannular ring section surface 33.

The two partial movements, that is, the pivot movement and the advancemovement take place steadily and simultaneously, so that it is possible,despite a pivoting of the embossing band 11 about Y instead of X, toachieve a roll-off movement about the center X. It is obvious andirrelevant for the explanation of the combined angular pivot advancemovement, that the same result is obtained if the angular pivot movementtakes place first, followed by the advance movement.

The above described arrangement can naturally also be used for printingon cylindrical workpieces, in which case the center line of theembossing band is set perpendicular to the cylinder axis and thetransmission of a pivot movement is foregone, for example, bydisengaging the connection between the guide piece 19 and the head 27.

Furthermore, conical workpieces can also be embossed where the apices ofthe cone lie on the driving side of the block, in which case thepivoting of the embossing band takes place in the opposite direction.

This way it is possible to provide a device for printing on workpieceswith an outer surface in the form of a truncated cone, which can beproduced in a spacesaving manner and which also has the advantage thatthe blocks can be produced in a simple manner.

What is claimed is:

1. A method for printing on an object having a conical outer surfacecomprising the steps of providing an object having a conical outersurface, providing a printing block having a corresponding conical outersurface, providing an elongated printing tape, rotating one of saidobject and said printing block about its geometric axis in drivingengagement with the other with the printing tape engaged therebetween tomove said printing tape in a first direction parallel to its length, andimparting a pivoting movement to said printing tape in a direction at anangle to said first direction about an imaginary axis perpendicular toits surface passing through the printing block.

2. The method of claim 1 wherein the center of an annular ring travelledby the block on the printing tape due to the two movements imparted tothe tape coincides with the geometric axis of the block.

3. A method as in claim 1 wherein said axis passes through theintersection of a line parallel to the longitudinal axis of the tape andthe contact line between the block and the tape.

4. Apparatus for printing on a workpiece having a non-cylindrical outersurface comprising a printing block having an outer surface ofsubstantially the same shape as the workpiece to be printed, anelongated printing tape, means for revolving one of said printing blockand workpiece in driving engagement with the other with the tapetherebetween to impart movement to said tape in a first directionparallel to its longitudinal axis, and means for pivoting said tape in adirection at an angle to said first direction about an imaginary axisperpendicular to the tape surface passing through the printing block.

5. Apparatus as in claim 4 wherein said revolving means comprises meansfor revolving said block about its geometric axis.

6. Apparatus as in claim 4 wherein both said printing block and saidworkpiece are of conical shape and contact is made with said tape bysaid block and said workpiece over a sector of an annular ring duringthe revolving of said block and workpiece and the movement of said tapein said first direction, the center of the ring sector lying on a linecorresponding to the geometric apex of the cone shaped block.

7. Apparatus as in claim 4 wherein said means for imparting the pivotingmotion to said tape comprising an articulated parallelogram arm linkage,said tape being parallel to one of the arms of said linkage.

8. Apparatus as in claim 4 wherein said revolving means comprises meanswhich are linked to the means for imparting a pivoting motion to thetape.

9. Apparatus as in claim 4 wherein each of said printing block and saidworkpiece are generally conical in shape and are located with the baseends adjacent one another.

10. Apparatus as in claim 4 further comprising means for controlling theangle of the pivoting motion imparted to said tape.

1. A method for printing on an object having a conical outer surfacecomprising the steps of providing an object having a conical outersurface, providing a printing block having a corresponding conical outersurface, providing an elongated printing tape, rotating one of saidobject and said printing block about itS geometric axis in drivingengagement with the other with the printing tape engaged therebetween tomove said printing tape in a first direction parallel to its length, andimparting a pivoting movement to said printing tape in a direction at anangle to said first direction about an imaginary axis perpendicular toits surface passing through the printing block.
 2. The method of claim 1wherein the center of an annular ring travelled by the block on theprinting tape due to the two movements imparted to the tape coincideswith the geometric axis of the block.
 3. A method as in claim 1 whereinsaid axis passes through the intersection of a line parallel to thelongitudinal axis of the tape and the contact line between the block andthe tape.
 4. Apparatus for printing on a workpiece having anon-cylindrical outer surface comprising a printing block having anouter surface of substantially the same shape as the workpiece to beprinted, an elongated printing tape, means for revolving one of saidprinting block and workpiece in driving engagement with the other withthe tape therebetween to impart movement to said tape in a firstdirection parallel to its longitudinal axis, and means for pivoting saidtape in a direction at an angle to said first direction about animaginary axis perpendicular to the tape surface passing through theprinting block.
 5. Apparatus as in claim 4 wherein said revolving meanscomprises means for revolving said block about its geometric axis. 6.Apparatus as in claim 4 wherein both said printing block and saidworkpiece are of conical shape and contact is made with said tape bysaid block and said workpiece over a sector of an annular ring duringthe revolving of said block and workpiece and the movement of said tapein said first direction, the center of the ring sector lying on a linecorresponding to the geometric apex of the cone shaped block. 7.Apparatus as in claim 4 wherein said means for imparting the pivotingmotion to said tape comprising an articulated parallelogram arm linkage,said tape being parallel to one of the arms of said linkage. 8.Apparatus as in claim 4 wherein said revolving means comprises meanswhich are linked to the means for imparting a pivoting motion to thetape.
 9. Apparatus as in claim 4 wherein each of said printing block andsaid workpiece are generally conical in shape and are located with thebase ends adjacent one another.
 10. Apparatus as in claim 4 furthercomprising means for controlling the angle of the pivoting motionimparted to said tape.